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Gold | Silver |
Platinum
GOLD
Gold is a highly sought-after precious metal that for
many centuries has been used as money, a store of value and in jewelry. The
metal occurs as nuggets or grains in rocks and in alluvial deposits and is
one of the coinage metals. It is a soft, shiny, yellow, dense, malleable,
and ductile (trivalent and univalent) transition metal.
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OCCURANCE Gold is found
in igneous rocks and in associated quartz veins, often in
small quantities invisible to the naked eye. It is also concentrated in
secondary "placer" deposits - as nuggets or grains in river sands and
gravels. Gold may still be extracted from placer deposits by the traditional
panning method, but modern commercial mining involves large earth-moving
machinery and concentrated acids for processing the ore. The main
gold-bearing rocks occur in Africa, California and Alaska (USA), Canada, the
former USSR, South America, and Australia. |
| The colour of gold depends upon the amount and type of impurities it
contains. Native gold is typically golden yellow, but in order to vary its colour and increase its hardness for use in jewelry, gold may be alloyed to
other metals. Silver, platinum, nickel, or zinc may be added to give a pale
or white gold. Copper is added for red or pink gold; iron for a tinge of
blue. Gold purity is defined by the proportion of pure gold metal present,
and this is expressed as its carat (ct) value. The purity of gold used in
jewelry varies from 9 carat (37Yz per cent or more pure gold), through 14,
18, and 22 carat, to 24 carat, which is pure gold. In many countries, gold
is "hallmarked" to indicate its degree of purity. |
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| Gold has a long and complex history. From gold’s first discovery, it has
symbolized wealth and guaranteed power. Gold has caused obsession in men and
nations, destroyed some cultures and gave power to others. Over the
centuries, most of the Egyptian tombs were raided, but the tomb of
Tutankhamen was discovered undisturbed by modern archaeologists. Inside the
largest collection of gold and jewelry in the world was found and included a
gold coffin whose quality showed the advanced state of Egyptian
craftsmanship and goldworking (second millennium BC) The Persian Empire, in
what is now Iran, made frequent use of Gold in artwork as part of the
religion of Zoroastrianism. Persian goldwork is most famous for its animal
art, which was modified after the Arabs conquered the area in the 7th
century AD. |
Ancient gold statue of Lord Buddha |
Tutankhamen's death mask made of gold inlaid with
colored glass and semiprecious stone. |
A gold statue inside the an Egyptian
pyramid. |
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Gold’s superior electrical conductivity, malleability,
and resistance to corrosion have made it vital to the manufacture of
components used in a wide range of electronic products and equipment,
including computers, telephones, cellular phones, and home appliances |
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The rise of a gold standard was meant to stabilize
the global economy, dictating that a nation must limit its issued
currency to the amount of gold it held in reserve. Great Brittain was
the first to adopt the gold standard in 1821, followed, in the 1870s, by
the rest of Europe followed. The system remained in effect until the end
of the first world war, after which the US was the only country still
honoring the Gold Standard. After the war, other countries were allowed
to keep reserves of major currencies instead of gold. The arrival of the
great depression marked the end of the U.S. export of gold in the 1930s.
By mid 20th century, the US dollar had replaced gold in international
trade. |
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Natural Gemstones |
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